I have given up on the idea of using Locos with external antennas. Every Loco with unbalanced (weak internal and strong external) antennas will mess up AirMax for the other clients. And using a Loco with only an external antenna defeats the purpose of AirMax.
If it isn't close enough to run the Loco with both internal antennas, it gets a Rocket with the dual polarity yagi. A Rocket with a dual-pol yagi is unbeatable.